Filing attachment for portable power tools



R. w. GASKINS I FILING mncnuzm FOR PORTABLE POWER TOOLS Fiied'F'eb.'l7, 1958 Dc. s, 1960 2 Sheets-Sheet 1 INVENTOR. ROEERT W. GASKINS Dec. 6, 1960 R. w. GASKINS 2,962,798

FILING ATTACHMENT FOR PORTABLE POWER TOOLS Filed Feb. 17, 1958 2 Sheets-Sheet 2 INVENTOR. Hm WW ROBE RT w. sAsKms BY gitudinally of the file F so that any desired amount of overhang may be provided in order to adapt the tool to various operational needs. Close to the rollers, support is provided by the handle 40 which is adjustably secured to frame 22.

Frame members 30 and 32 are normally fitted for each pair of rollers 24 and 26 so that the bearing openings for shafts 28 and 29 will be so placed as to space the rollers apart an amount that will properly accept the type of file being used and give sufficient clearance so that the file can be reciprocated through the rollers without damaging the same or causing the files themselves to bind. This clearance is normally obtained by trial. In some instances it is desirable to remove roller 24 and to facilitate this shaft 28 is headed on one end and provided with suitable locking means at the other end. With files having teeth of different depths, it being desirable, in so many operations, to have enough movement possible so that the file can, in effect, cut on its working stroke as its cutters are properly presented for cutting and then, on the return stroke there will be enough clearance so that any chips cut from the work piece will have a chance to be discarded by the file before the next succeeding cutting troke occurs.

For certain forms of pattern making, particularly, it may be necessary to use various portions throughout the length of file F and at the same time to have the file supported in a manner that will permit putting face pressure on the same. Under such conditions the slightly modified form as illustrated in Figure 6 may be desirable in which a shaft member 42 is provided and disposed for sliding in a suitable bearing 44 secured to motor housing 10. A locking means, as the wing-nut and clamp device shown at 46, is provided to hold shaft 42 in adjusted position. Fixedly secured to shaft 42 at its opposite ends are the handles 48 and 49. Also secured to shaft 42 in a fixed manner and quite often made as part of handle assembly 49 is the roller support means 51, which in turn positions roller 24 and 26. Figure 6 illustrates a further modified form of this equipment in which an air motor 13 is employed and this is supplied, by a suitable air hose 17, from a source of air under pressure. There are many forms of air motors which are adapted to producing a reciprocating motion on their output shaft or spindle and any of these accepted types would be satisfactory for this use.

It is desirable to use files or rasps that are commercially available owing to the fact that tools of this order are not normally used in full scale production but more often are used in the development stages or in jobbing shops and the like where it will be very desirable to be able to use a wide variety of files, scrapers or rasps. Consequently if the machine equipment is capable of accepting a conventional form of these cutting tools it will be generally more useful for its purpose.

Figure 7 is a modified form of this tool driven by a very small electric motor 80. This form of the tool is provided, preferably, with a reversed bevel pinion 82 driving a narrow toothed gear 84. This gear has secured to it a driving detent 76 and is used to reciprocate a shaft 58 in the same general manner as the showing of Figure 1. The clamping means for the file F is similar to that employed in the other forms of equipment except scaled down in size. This unit is intended primarily as an inexpensive small filing tool that would find particular adaptability in model building. As compactness and lightness are required, motor 80 of necessity must operate at high speed and preferably be provided with reduction gear means.

A preferred form of file holder is shown throughout the various views as in Figures 1, 2, 3 and 6. A first clamp member 50 and a second clamp member 52 are provided with spaced and parallel planar surfaces arranged with clamping bolts 54 so as to firmly engage file F. A portion of clamp member 52, which has considerably greater extent along the axis of the file than clamp member 50, provides a cylindrical coupling member 56 adapted to engage the reciprocating shaft 58 and an axial aligned groove 57 adapted to assist in engaging round or triangular files. Normally a key member, as a tapered pin, is provided at 60 and a headless set screw is provided at 62 so that the shaft may be engaged with sufficient firmness to transfer its reciprocating motion to the clamp and file assembly and allow the utilization of round, triangular and half-round shaped files and rasps. A visual inspection access opening to insure proper seating of the file is shown at 63.

A very satisfactory reciprocating mechanism is shown in Figures 1 and 2 in which the motor driven pinion 70 drives a gear 72 of considerable diameter, and provides an appreciable reduction in speed from the relatively high speed of motor 11. This motor is driven at a high rotative speed so that it may deliver a high power output with a minimum of weight. Gear 72 is suitably journalled by shaft 74 and is provided on its free face with the driving detent 76. Detent 76 engages a channellike member disposed at right angles to shaft 58 as indicated at 78. The function of these parts will be clearly understood, it is believed, when it is considered that shaft 58 is capable of longitudinal movement, or reciprocation and the transverse channel member 78 is fixedly secured to shaft 58. Therefore, as gears 70 and 72 drive and carry the detent 76 around in a circular path while it is engaged in channel 78, shaft 58 will be moved longitudinally and thus be able to reciprocate file F. Spaced bearings are provided in housing 10 for shaft 58 and these bearings must have sufficient length to adequately support the shaft during reciprocation and to also prevent bending of the shaft in use. The speed of this reciprocation is basically controlled by the speed of motor 11 and the gear ratio between pinion 70 and gear 72 and is further modified by rheostat 18 which controls the flow of electric current to motor 11.

Throughout this specification and the accompanying drawings, preferred form of this tool has been illustrated. However, it is believed apparent, that the form and driving means for the reciprocating mechanism may be varied to suit the various operational conditions encountered. It follows that either electricity or air may be used to power the tool. Likewise, it will be obvious that many types of files F might be employed. These could vary from the rasp type of file capable of quickly surfacing wooden or soft metal parts down through various cuts of files ending in the Vixen type of files and certain forms of scrapers used for cutting very fine scrapings from metal parts.

It is believed that it will be clearly apparent from the above description and the disclosure in the drawings that the invention comprehends a novel construction of a filing attachment for portable electric powered and air driven tools.

Having thus disclosed the invention, I claim:

1. A filing attachment for portable power tools having a reciprocating shaft and a housing therefor comprising: a replaceable file disposed substantially coaxial with said shaft; a quickly adjustable file clamp formed of two coacting members, a base clamp member having a cylindrical portion adapted to engage said shaft, a file clamp member coacting with said base member to engage said file and provide an abutment for the exposed end of said reciprocating shaft and clamping bolts for securing the two members in clamping relationship with said file; means for fixedly securing said base clamp member to said reciprocating shaft; an inspection access in said file clamp member to permit inspection of the seating of the file; guide means for said file secured to said housing adapted to support the file at various adjusted positions throughout its length, and said guide means comprising two spaced apart rollers disposed transversely of the file and on each face of the same to accept thrust as either side of the file is used, said rollers spaced apart by interchangeable frame members so the spacing can be readily adjusted to the file thickness and a handle disposed in proximity to said rollers and adjustably positioned by the same means used to adjust the position of said rollers.

2. A filing attachment for portable power tools having a power driven reciprocating shaft and a housing therefor; a replaceable file disposed substantially coaxial with said shaft; a file clamp comprising two coacting members, a base clamp member having a cylindrical portion adapted to engage said shaft, a file clamp member coacting with said base member to engage said file and readily loosened clamping means for securing the two members in clamping relationship with the file; demountable means for securing said base clamp member to said reciprocating shaft; guide means for said file secured to said housing adapted to support the file at various adjusted positions throughout its length; a handle adjustably positioned adjacent said guide means; and said guide means comprising a pair of rollers disposed transversely of the file to accept thrust as either side of the file is used one on each face of the same and means to vary the spacing of said rollers to adapt them to the thickness of the file being used and a handle positioned adjacent said rollers.

3. A filing tool for portable power use; comprising: a power driven gear of considerable diameter having a driving detent on its free face and a housing therefor; a reciprocatable shaft disposed diametrically of said gear; a crosshead of channel shape disposed transversely of said shaft and in operative engagement with said detent; a replaceable file disposed substantially coaxial with said shaft; spaced bearings of sufiicient length to support said shaft in the full range of its reciprocation, said bearings disposed on opposite sides of said gear in a manner to adequately support said shaft during the transfer of power from the detent to said shaft and during periods when face pressure is applied to the file being used; a file clamp formed of two coacting members, a base clamp member having a cylindrical portion to engage said shaft, a file clamp member coacting with said base member to engage said file and clamping bolts for securing the two members in clamping relationship with the file; means for fixedly securing said base clamp member to said reciprocating shaft; guide means for said file, secured to said housing, and adapted to support the file at various adjusted positions throughout its length; said guide means comprising two spaced apart rollers disposed transversely of and in engagement one with each face of said file to accept thrust as either side of the file is used and a handle secured in proximity with said rollers and adjustably positioned therewith.

4. An adjustable clamp for use on portable filing machines employing a file and a reciprocating file driv ing shaft, comprising: a first clamp member and a second clamp member adapted to coact to engage and secure said file to said reciprocating file driving shaft of a portable filing machine; said second clamp member having an interrupted planar surface portion adapted to provide two spaced clamp surfaces for a file and having a longitudinally and medially disposed groove adapted to provide a seat for one end of said file driving shaft; said second clamp member having a cylindrical coupling member made integral therewith and disposed at one end of said second clamp member and in axial alignment with said groove; said first clamp member having a planar surface disposed to coact with the planar portions of said second clamp member; clamping bolts disposed on opposite sides of said groove and passing through both said first and said second clamp members and adapted to secure them in clamping relationship on the opposite sides of a file.

5. The subject matter of claim 4 in which there is an inspection opening passing through said first clamp member at right angles to the face of said file; the cylindrical portion of said coupling member adapted to be fixedly positioned on said reciprocating shaft so the end of said shaft will be visible in said inspection opening in relationship to the end of the file being clamped in position and thus make it possible to determine when the file is in abutting engagement with said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 974,474 Curtis Nov. 1, 1910 1,174,890 Naylor Mar. 7, 1916 1,257,455 Braun Feb. 26, 1918 1,617,410 Meyer Feb. 15, 1927 1,734,212 Johnston Nov. 5, 1929 1,742,862 Jones Jan. 7, 1930 1,793,053 Cahill et al. Feb. 7, 1931 2,122,611 Kirby July 5, 1938 2,764,188 Hoffman Sept. 25, 1956 2,812,963 Iohansson Nov. 12, 1957 OTHER REFERENCES Scientific American, April 1944, page 1177, 

